#define _CRT_SECURE_NO_WARNINGS 1
bool isMirror(struct TreeNode* root1, struct TreeNode* root2)
{
    if (root1 == NULL && root2 == NULL)
        return true;

    if (root1 == NULL || root2 == NULL)
        return false;

    return root1->val == root2->val && isMirror(root1->left, root2->right)
        && isMirror(root1->right, root2->left);
}
bool isSymmetric(struct TreeNode* root)
{
    return isMirror(root->left, root->right);
}